A program directed toward the synthesis and bioorganic chemistry of various antitumor natural products is proposed. In this program new synthetic strategies will be explored and new reaction types will be investigated. In the category of the new chemistry to be explored are (a) reactions of diazo compounds with thioamides as a versatile route to enamines, (b) the use of furan surrogates for the anomeric carboxyl function of sialoconjugates, (c) enantiospecific iodolactonizations, (d) the use of epoxyendiolides as external electrophiles, and (e) interactive Lewis acid catalysts. Experiments designed to further clarify the bioorganic chemistry of the mitomycins and camptothecin, as well as sakyomycin are envisioned. New synthetic strategies will be directed toward either the total synthesis or the synthetic modifications of the following natural products: (i) mitomycins, (ii) gangliosides, (iii) pancratistatin, (iv) echinosporin, (v) sakyomycin, (vi) FR 900506, (vii) harringtonines, (viii) camptothecin, (ix) gilvocarcin, (x) tunicamycin, (xi) anguidine and (xii) spicamycin.